Cluster-randomized controlled trial evaluating the effectiveness of computer-assisted intervention delivered by educators for children with speech sound disorders

Purpose: The aim was to evaluate the effectiveness of computer-assisted input-based intervention for children with speech sound disorders (SSD).  Method: The Sound Start Study was a cluster randomized controlled trial. Seventy-nine early childhood centers were invited to participate, 45 were recruited, and 1,205 4- to 5-year-old children’s parents/educators returned questionnaires. Children whose parents/educators had concerns about speech were assessed (n=275); 132 children who were identified with phonological impairment of unknown origin underwent additional assessment. Children with SSD and no receptive language or hearing difficulties, typical non-verbal intelligence, and English as their primary language were eligible; 123 were randomized (Intervention n=65; Control n=58); 3 withdrew. Intervention involved Phoneme Factory Sound Sorter software administered by educators over 9 weeks; Control involved typical classroom practices. Participants were re-assessed twice by a speech-language pathologist (SLP) blinded to the initial assessment and intervention conditions.  Results: For the primary outcome variable (percentage of consonants correct), the significant mean change from pre- to post-intervention for the Intervention group (mean change+6.15, p<.001) was comparable in magnitude to the significant change for the Control group (mean change+5.43, p<.001) with a small between groups effect size for change (Cohen’s d=0.08). Similar results occurred for measures of emergent literacy, phonological processing,participation, and wellbeing.  Conclusion: Computer-assisted input-based intervention administered by educators did not result in greater improvement than typical classroom practices.